I’ve been having a similar problem: I use 2 objects of the same character, an animated one, purely for animations and a ragdoll one, maybe using a set up like this will help? (tutorial for this: How to do Easy Unity3D Ragdoll Physics with Source Code - unity ragdoll tutorial - YouTube)
In case anyone is following this question for the same reason I was, that is, if your skinned mesh renderer component stays put while your ragdoll moves (giving the consequence that if the camera doesn’t show the position where the SMR is, it doesn’t render the ragdoll), the solution to that issue in my case was assigning the Hips bone as the Root Bone for the skinned mesh renderer (instead of the rig’s root bone).